Most wastewater treatment plants use aeration basins in the treatment process. In an aeration basin, diffusers add oxygen to the water because the bacteria that feed on and break down the organic material need oxygen. When oxygen levels in the wastewater decrease, the bacteria stop feeding on and metabolizing the organic matter. As the diffusers become blocked with waste material, less oxygen is aerated into the wastewater, and the bacteria are less productive. Diffusers must be cleaned in order to maintain bacteria activity.
Aeration basin diffusers must be cleaned manually through a long and sometimes expensive process. Ceramic systems must be cleaned with gas, acid or hydrogen chloride. For rubber systems, the entire system must be shut down and the built-up waste product scraped from the diffusers. Further, aeration basins may contain hundreds of diffusers, and a single wastewater treatment plant may have hundreds to thousands of diffusers in all basins. Both the materials and labor make cleaning the diffusers a costly task, especially if done before it is necessary.
A problem with current aeration basin diffuser systems is the inability to tell when diffusers require cleaning. A very small increase in dynamic wet pressure across a diffuser indicates a diffuser may need to be cleaned; however, current devices used to read changes in dynamic wet pressure and indicate the need for diffuser cleaning have failed to properly indicate and continuously monitor pressure across diffusers.
For example, U.S. Pat. No. 6,200,468 describes a pressure reading system used to determine when diffusers require cleaning. The system comprises a portable panel, which must be stored when not in use, and two pressure gages. One pressure gauge measures the dynamic wet pressure of the diffuser, while the second pressure gauge measures the pressure drop through the orifice. The system operator then uses a chart to determine the air flow rate and whether or not the diffusers need cleaning.
One problem known with this current panel system is its portability. It is cumbersome to set up, and the panel components are regularly damaged from the constant assembly, disassembly and improper storage. Further, operators often neglect to take regular readings because of the setup involved with the current panel system. Operators occasionally fail to take readings for great periods of time, resulting in decreased bacteria function and increased power consumption.
In addition, the panels fail to operate properly over time. For example, lines plug and gauges fail. Both improper handling and the panel's construction as a portably system make the lines and gauges vulnerable to inoperability. The lines and gauges are also exposed to the contaminated wastewater, which requires the panel system to be cleaned and maintained regularly.
The current system also requires an operator to interpret the results. Inexperienced, hurried or otherwise distracted operators may mistakenly determine the diffusers do not need to be cleaned when, in actuality, the wastewater basin does not contain sufficient aeration for the bacteria to metabolize.